1. Field of Invention
The present invention is directed to a beamforming device. More particularly, the present invention is directed to a method and apparatus for combining and collimating light through the atmosphere.
2. Description of Related Art
Presently, lighting systems can be used to transmit light. This transmitted light can be used to communicate data between a source and a receiver. For example, data may be transmitted from a source across fiber optics to a receiver. Additionally, the transmitted light can be used to pinpoint objects. For example, a laser sight can be used to pinpoint a target. Furthermore, transmitted light can be used for engraving purposes. For example, high power radar can utilize transmitting light for target illumination.
Unfortunately, many present lighting systems do not provide adequate power for numerous applications. Furthermore, it can be cost and space prohibitive to increase the power of the light for use in numerous applications. For example, it is cost prohibitive to transmit high-speed data across the atmosphere because of the necessary power requirements. Also, cost and size constraints can prohibit the use of a large lighting system for many applications, such as systems for pinpointing targets. For example, presently the highest power laser diodes cannot produce more than one to four Watts of power. This power can be insufficient for making a three-dimensional rendering of a battle scene when dense atmospheric conditions are present.
The present invention provides a nonimaging beam combiner and collimator (NIBCC). The NIBCC can include at least two first light sources that emit light of the same wavelength through a focus point and a nonimaging element that receives the light of the same wavelength after the focus point and collimates the light of the same wavelength through the atmosphere. The at least two first light sources can include at least one of fiber light sources, optical fibers, gradient index lenses, fiber lasers and laser diodes. The collimator can include an input surface, a paraboloid surface located adjacent to the input surface, a conical surface located adjacent to the paraboloid surface, and an ellipsoid surface located adjacent to the conical surface and located on an opposite side of the collimator from the input surface. The paraboloid surface uses total internal reflection principals.
The NIBCC can further include at least two second light sources, the at least two second light sources emitting light of a same second wavelength through the focus point. The nonimaging element can further receive the light of the same second wavelength after the focus point and collimate the light of the same second wavelength to sum the power of the light of the same second wavelength through the atmosphere.
The NIBCC can additionally include a light source controller coupled to at least one of the at least two first light sources and an atmospheric condition sensing device coupled to the light source controller. The light source controller can control light emitted by at least one of the at least two first light sources based on atmospheric conditions sensed by the atmospheric condition sensing device. The light source controller can also cause the at least one of the at least two first light sources to stop emitting light when the atmospheric condition sensing device senses that the atmosphere transmits light easily. The light source controller can further cause the at least one of the at least two first light sources to emit light when the atmospheric condition sensing device senses that the atmosphere does not transmit light easily. The atmospheric condition sensing device can include a laser radar. The light source controller can perform at least one of boosting, maintaining and lowering the power of light through the atmosphere based on atmospherics sensed by the atmospheric sensing device. The atmospheric condition sensing device can sense atmospheric conditions within a beam of the light of the same first wavelength through the atmosphere.
The NIBCC can be utilized in an engraver. The NIBCC can also be utilized in a target pointing system for targeting an object.
The NIBCC can additionally be utilized in an atmospheric optical network. The atmospheric optical network can include an atmospheric optical data node. The atmospheric optical data node can include at least two first light sources, the at least two first light sources emitting light of a same first wavelength through a focus point. The atmospheric optical data node can also include at least two second light sources, the at least two second light sources emitting light of a same second wavelength through the focus point. The atmospheric optical data node can further include a nonimaging element that receives the light of the same first wavelength after the focus point and collimates the light of the same first wavelength to sum a power of the light of the same first wavelength through the atmosphere and receive the light of the same second wavelength after the focus point and collimate the light of the same second wavelength to sum the power of the light of the same second wavelength through the atmosphere. The atmospheric optical network can also include a second atmospheric optical data node.
The atmospheric optical network can additionally include a receiver that receives the light of the same first wavelength and the light of the same second wavelength from the atmosphere. The receiver can be located approximately at least two kilometers, 10 kilometers, or more from the apparatus for combining and collimating light. The receiver can include a wavelength division demultiplexer that demultiplexes the light of the same first wavelength from the light of the same second wavelength. The receiver can also include an add/drop multiplexer.
The atmospheric optical network can further include a reflector that reflects the collimated light through the atmosphere. The atmospheric optical network can also include a refractor that refracts the collimated light to a first receiver and a second receiver.
The atmospheric optical network can additionally include a light source controller coupled to at least one of the at least two first light sources and an atmospheric condition sensing device coupled to the light source controller. The light source controller can control light emitted by the at least one of the at least two first light sources based on atmospheric conditions sensed by the atmospheric condition sensing device. The light source controller can also cause the at least one of the at least two first light sources to stop emitting light when the atmospheric condition sensing device senses that the atmosphere transmits light easily. The light source controller can additionally cause the at least one of the at least two first light sources to emit light when the atmospheric condition sensing device senses that the atmosphere does not transmit light easily.
The atmospheric condition sensing device can include a laser radar. The light source controller can boost, maintain or lower the power of light through the atmosphere based on atmospherics sensed by the atmospheric sensing device. The atmospheric condition sensing device can sense atmospheric conditions within a beam of the light of the same first wavelength through the atmosphere.
The NIBCC offers the following advantages: It achieves a high quality collimated beam with 0.5 mrad divergence. Also, it is mechanically rugged and does not require periodic alignment during the operation, even under battlefield conditions. Additionally, it is inexpensively mass produced by either molding or diamond-turning technologies. Furthermore, it is transparent to enemy radar in battlefield application because it can be made without metal elements; therefore, it supports stealth technology. Also, it is very compact; 10 times smaller than a conventional optics approach. The size of the NIBCC can be  less than 2xe2x80x3xc3x972xe2x80x3xc3x973xe2x80x3. Additionally, it is stable against contamination with an outer surface that can be easily cleaned. Furthermore, it provides phase coherent collimation at microwave modulation frequencies of 1 GHz because the optical path difference in the NIBCC can be designed to be much less than the coherence length of a 1 GHz microwave signal. Also, it provides high efficiency ( greater than 98% transmission, with antireflection coating on the NIBCC) light collimation. Additionally, potential aberrations of individual beams can be small because the more beams the NIBCC combines, the smaller every partial aperture of the entrance beam. Furthermore, the NIBCC can combine beams of the same wavelength.
The NIBCC can be very inexpensive and can maintain its stability in the presence of temperature deviations and vibrations. Because of its ability to achieve high brightness in small, solid angles, it will be attractive in many commercial applications such as airport landing lights, unidirectional warning approach lights for high masts, police searchlights, and helicopter approach lights.